EGG-YOLK REACTION OF STAPHYLOCOCCUS PYOGENES

One thousand isolates of Staph, pyogenes were examined for the egg-yolk reaction, using solid medium and the results correlated with the antibiotic sensitivity and bacteriophage type of the strains. Most of the egg-yolk positive organisms were found amongst those isolates which were sensitive to all antibiotics tested, or resistant only to penicillin or tetracycline. Egg-yolk negative isolates occurred mainly in a group of staphylococci showing resistance to three or more antibiotics. Fifty-five per cent of these negative strains were bacteriophage type 84/85. © 1969 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.